Non-combustible aerosol provision system

ABSTRACT

The present disclosure relates to a method of operating an non-combustible aerosol provision system including control circuitry, a power source and an aerosol generator configured to generate an aerosol from an aerosolizable material. The control circuitry causes delivery of power from the power source to the aerosol generator for an aerosol generation event in response to a user input; and determines the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the determined rate of aerosol generation is adjusted based on a dynamic factor.

PRIORITY CLAIM

The present application is a National Phase entry of PCT Application No. PCT/GB2021/051096, filed May 6, 2021, which claims priority from GB Application No. 2006778.1, filed May 7, 2020, each of which is hereby fully incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to non-combustible aerosol provision systems such as electronic smoking articles and the like.

BACKGROUND

Non-combustible aerosol provision systems (e.g., e-cigarettes/tobacco heating products) generally contain an aerosolizable material, such as a reservoir of a source liquid containing a formulation, typically including nicotine, or a solid material such as a tobacco-based product, from which an aerosol is generated for inhalation by a user, for example through heat vaporization. Thus, an non-combustible aerosol provision system will typically comprise an aerosol generation chamber containing a vaporizer, e.g. a heater, arranged to vaporize a portion of aerosolizable material to generate an aerosol in the aerosol generation chamber. As a user inhales on the device and electrical power is supplied to the heater, air is drawn into the device and into the aerosol generation chamber where the air mixes with the vaporized aerosolizable material and forms a condensation aerosol. There is a flow path between the aerosol generation chamber and an opening in the mouthpiece so the air drawn through the aerosol generation chamber continues along the flow path to the mouthpiece opening, carrying some of the condensation aerosol with it, and out through the mouthpiece opening for inhalation by the user.

Once the initial amount of liquid is consumed, the user must replace the aerosolizable material. In the case of e-cigarettes, this is generally done by either re-filling the device with liquid only (possible in so-called “open” systems) or by replacing the entire unit which contained the liquid with a new liquid containing unit (so-called “closed” systems).

In the case of non-combustible tobacco heating products, the aerosolizable material is generally incorporated within a solid material which is typically heated so as to generate a condensation aerosol. Similarly to e-cigarettes, such devices typically contain a finite source of aerosolizable material such that either the specific solid material which is being heated needs replaced/replenished (as may be the case in loose-leaf tobacco heating products), or an article containing the solid aerosolizable material is replaced/replenished.

SUMMARY

Approaches are described herein which seek to help provide new approaches to monitoring the consumption of the aerosolizable material.

In one aspect of the present disclosure there is provided a method of operating an non-combustible aerosol provision system comprising control circuitry, a power source and an aerosol generator configured to generate an aerosol from an aerosolizable material, wherein the control circuitry performs the method of causing delivery of power from the power source to the aerosol generator for an aerosol generation event in response to a user input, and determining the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the determined rate of aerosol generation is adjusted based on a dynamic factor.

In a further aspect of the present disclosure there is provided a control unit for use with an electronic non-combustible aerosol provision device comprising: a power source; and control circuitry configured to cause the delivery of power from the power source to an aerosol generator for an aerosol generation event in response to a user input, wherein the aerosol generator is configured to generate an aerosol from an aerosolizable material during the aerosol generation event; wherein the control circuitry is further configured to determine the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor.

In a further aspect of the present disclosure there is provided a non-combustible aerosol provision system comprising: a control unit comprising: a power source; and control circuitry configured to cause the delivery of power from the power source to an aerosol generator for an aerosol generation event in response to a user input, wherein the aerosol generator is configured to generate an aerosol from an aerosolizable material during the aerosol generation event; wherein the control circuitry is further configured to determine the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor; the aerosol generator; and the aerosolizable material.

In a further aspect of the present disclosure there is provided a non-combustible aerosol provision means comprising: power source means; control means configured to cause the delivery of power from the power source means to an aerosol generator means for a period of time in response to a user input, wherein the aerosol generator means is configured to generate an aerosol from an aerosolizable material means; and wherein the control means is further configured to determine the amount of aerosol generated from the aerosolizable material means, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor.

These and other aspects as apparent from the following description form part of the present disclosure. It is expressly noted that a description of one aspect may be combined with one or more other aspects, and the description is not to be viewed as being a set of discrete paragraphs which cannot be combined with one another.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 schematically represents in cross-section a non-combustible aerosol provision system in accordance with certain embodiments of the disclosure.

FIG. 2 schematically represent certain operations for non-combustible aerosol provision systems in accordance with certain embodiments of the disclosure.

FIG. 3 is a diagram representing the rate of mass loss for repeats of different length heater activations of an non-combustible aerosol provision system in accordance with certain embodiments of the disclosure.

DETAILED DESCRIPTION

Aspects and features of certain examples and embodiments are discussed/described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed/described in detail in the interests of brevity. It will thus be appreciated that aspects and features of apparatus and methods discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.

According to the present disclosure, a “non-combustible” non-combustible aerosol provision system is one where a constituent aerosol-generating material of the non-combustible aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, which may also be known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement.

In some embodiments, the non-combustible aerosol provision system is an aerosol-generating heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system.

In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.

Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and a consumable for use with the non-combustible aerosol provision device.

In some embodiments, the non-combustible aerosol provision system, or the non-combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energized so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

Non-combustible aerosol provision systems often, though not always, comprise a modular assembly including both a reusable part (also referred to as a control unit) and a replaceable/disposable cartridge part (also referred to as a consumable part). Often the replaceable cartridge part will comprise the aerosolizable material and the vaporizer and the reusable part will comprise the power supply (e.g. rechargeable battery), activation mechanism (e.g. button or puff sensor), and control circuitry. However, it will be appreciated these different parts may also comprise further elements depending on functionality. For example, for a so-called hybrid device the cartridge part may also comprise an additional flavor element, e.g. a portion of tobacco, provided as an insert (sometimes referred to as a “pod”) to add flavor to an aerosol generated elsewhere in the system. In such cases the flavor element insert may itself be removable from the disposable cartridge part so it can be replaced separately from the cartridge, for example to change flavor or because the usable lifetime of the flavor element insert is less than the usable lifetime of the aerosol generating components of the cartridge. The reusable device part will often also comprise additional components, such as a user interface for receiving user input and displaying operating status characteristics.

For modular devices a cartridge and control unit are electrically and mechanically coupled together for use, for example using a screw thread, magnetic, latching or bayonet fixing with appropriately engaging electrical contacts. When the aerosolizable material in a cartridge is exhausted, or the user wishes to switch to a different cartridge having a different aerosolizable material, a cartridge may be removed from the control unit and a replacement cartridge attached in its place. Devices conforming to this type of two-part modular configuration may generally be referred to as two-part devices or multi-part devices.

It is relatively common for non-combustible aerosol provision systems, including multi-part devices, to have a generally elongate shape and, for the sake of providing a concrete example, certain embodiments of the disclosure described herein will be taken to comprise a generally elongate multi-part device employing disposable cartridges which include an aerosolizable material and electric heater for vaporizing the aerosolizable material to form a condensation aerosol for user inhalation during use. However, it will be appreciated the underlying principles described herein may equally be adopted for different configurations of non-combustible aerosol provision systems, for example single-part devices or modular devices comprising more than two parts, refillable devices and single-use disposable devices, hybrid devices which have an additional flavor element, as well as devices conforming to other overall shapes, for example based on so-called box-mod high performance devices that typically have a more box-like shape or smaller form-factor devices such as so-called pod-mod devices. More generally, it will be appreciated embodiments of the disclosure may be based on non-combustible aerosol provision systems configured to incorporate the principles described herein regardless of the specific format of other aspects of such non-combustible aerosol provision systems.

FIG. 1 is a cross-sectional view through an example non-combustible aerosol provision system 1 in accordance with certain embodiments of the disclosure. The non-combustible aerosol provision system 1 comprises two main components, namely a control unit 2 (which may, for example, also be referred to as a reusable part) and a consumable part 4 (which may, for example, also be referred to as a replaceable/disposable cartridge part).

In normal use the control unit 2 and the consumable part 4 are releasably coupled together at an interface 6. When the consumable part is exhausted or the user simply wishes to switch to a different consumable part, the consumable part may be removed from the control unit and a replacement consumable part attached to the control unit in its place. The interface 6 provides a structural, electrical and air path connection between the two parts and may be established in accordance with conventional techniques, for example based around a screw thread, latch mechanism, or bayonet fixing with appropriately arranged electrical contacts and openings for establishing the electrical connection and air path between the two parts as appropriate. The specific manner by which the consumable part 4 mechanically mounts to the control unit 2 is not significant to the principles described herein, but for the sake of a concrete example is assumed here to comprise a latching mechanism, for example with a portion of the cartridge being received in a corresponding receptacle in the control unit with cooperating latch engaging elements (not represented in FIG. 1 ). It will also be appreciated the interface 6 in some implementations may not support an electrical connection between the respective parts. For example, in some implementations a vaporizer may be provided in the control unit rather than in the consumable part.

The consumable part 4 comprises a consumable housing 42 formed of a plastics material. The consumable housing 42 supports other components of the consumable part and provides the mechanical interface 6 with the control unit 2. The consumable housing 42 in this example is generally circularly symmetric about a longitudinal axis along which the consumable part couples to the control unit 2 and has a length of around 4 cm and a diameter of around 1.5 cm. However, it will be appreciated the specific geometry, and more generally the overall shapes and materials used, may be different in different implementations.

Within the consumable housing 42 is a reservoir 44 that contains liquid aerosolizable material. The liquid aerosolizable material may be conventional, and may be referred to as e-liquid. The liquid reservoir 44 in this example has an annular shape with an outer wall defined by the consumable housing 42 and an inner wall that defines an air path 52 through the consumable part 4. The reservoir 44 is closed at each end with end walls to contain the e-liquid. The reservoir 44 may be formed in accordance with conventional techniques, for example it may comprise a plastics material and be integrally molded with the consumable housing 42. The opening of the air path 52 at the end of the consumable part 4 provides a mouthpiece outlet 50 for the non-combustible aerosol provision system through which a user inhales aerosol generated by the non-combustible aerosol provision system during use.

The consumable part further comprises a wick 63 and a heater (vaporizer) 65 located towards an end of the reservoir 44 opposite to the mouthpiece outlet 50. In this example the wick 63 extends transversely across the cartridge air path 52 with its ends extending into the reservoir 44 of e-liquid through openings in the inner wall of the reservoir 44. The openings in the inner wall of the reservoir are sized to broadly match the dimensions of the wick 63 to provide a reasonable seal against leakage from the liquid reservoir into the cartridge air path without unduly compressing the wick, which may be detrimental to its fluid transfer performance.

The wick 63 and heater 65 are arranged in the cartridge air path 52 such that a region of the cartridge air path 52 around the wick 63 and heater 65 in effect defines a vaporization region for the consumable part. E-liquid in the reservoir 44 infiltrates the wick 63 through the ends of the wick extending into the reservoir 44 and is drawn along the wick by surface tension/capillary action (i.e. wicking). The heater 65 in this example comprises an electrically resistive wire coiled around the wick 63 and is discussed further below. In this example the wick 63 comprises a glass fiber bundle, but it will be appreciated the specific wick configuration is not significant to the principles described herein. In use electrical power may be supplied to the heater 65 to vaporize an amount of e-liquid (aerosolizable material) drawn to the vicinity of the heater 65 by the wick 63. Vaporized e-liquid may then become entrained in air drawn along the cartridge air path from the vaporization region to form a condensation aerosol that exits the system through the mouthpiece outlet 50 for user inhalation. Thus electrical power can be applied to the heater 65 to selectively generate aerosol from the e-liquid in the consumable part 4. When the device is in use and generating aerosol, the amount of power supplied to the heater 65 may be varied, for example through pulse width and/or frequency modulation techniques, to control the temperature and/or frate of aerosol generation as desired.

The general configuration of the wicking element and the heating element may follow conventional techniques. For example, in some implementations the wicking element and the heating element may comprise separate elements, e.g. a metal heating wire wound around/wrapped over a cylindrical wick, the wick, for instance, consisting of a bundle, thread or yarn of glass fibers. In other implementations, the functionality of the wicking element and the heating element may be provided by a single element. That is to say, the heating element itself may provide the wicking function. Thus, in various example implementations, the heating element/wicking element may comprise one or more of: a metal composite structure, such as porous sintered metal fiber media (Bekipor® ST) from Bekaert, a metal foam structure, e.g. of the kind available from Mitsubishi Materials; a multi-layer sintered metal wire mesh, or a folded single-layer metal wire mesh, such as from Bopp; a metal braid; or glass-fiber or carbon-fiber tissue entwined with metal wires. The “metal” may be any metallic material having an appropriate electric resistivity to be used in connection/combination with a battery. The “metal” could, for example, be a NiCr alloy (e.g. NiCr8020) or a FeCrAl alloy (e.g. “Kanthal”) or stainless steel (e.g. AISI 304 or AISI 316).

It will be appreciated the specific geometry and overall resistance of a heater in accordance with embodiments of the disclosure may be chosen having regard to the implementation at hand, for example having regard to the geometry of a wick 63 and air path 52 for an implementation of the kind shown in FIG. 1 , and also the desired amount of power to be dissipated in the heater during use and the power supply voltage. For the example the heater 65 may comprise around 10 turns of wire loosely wound around the wick 63 with an inner diameter of around 2.5 mm and that the thickness of the wire is appropriately chosen so the overall resistance of the electric heating is around 1.3 ohms. However, it will be appreciated different electric heater configuration having different electrical resistance may be used for other implementations, for example in other implementations the electric heater may have an electrical resistance within a range selected from the group comprising: 0.5 to 2 ohms, 0.8 to 1.8 ohms, 0.9 to 1.7 ohms, 1.0 to 1.6 ohms, 1.1 to 1.5 ohms and 1.2 to 1.4 ohms. Values below 0.5 Ohm could be used provided an appropriate power source is selected.

Turning now to the control unit 2, this comprises an outer housing 12 with an opening that defines an air inlet 28 for the non-combustible aerosol provision system, a battery 26 for providing operating power for the non-combustible aerosol provision system, control circuitry 20 for controlling and monitoring the operation of the non-combustible aerosol provision system, a user input button 14, an inhalation sensor (puff detector) 16, which in this example comprises a pressure sensor located in a pressure sensor chamber 18, and a visual display 24. The control circuitry is configured to monitor the output from the inhalation sensor to determine when a user is inhaling through the mouthpiece opening 50 of the non-combustible aerosol provision system so that power can be automatically supplied to the vaporizer 65 to generate aerosol in response to user inhalation. In other implementations there may not be an inhalation sensor for detecting when a user is inhaling in the device to automatically trigger aerosol generation and instead power may be supplied to the vaporizer in response to a user manually activating the button 14/switch to trigger aerosol generation. In still other implementations there may not be a user input button 14. In some of these implementations control circuitry 20 for controlling and monitoring the operation of the non-combustible aerosol provision system may continually monitor an inhalation sensor and may activate the device in response to a determination that the user is inhaling.

The outer housing 12 may be formed, for example, from a plastics or metallic material and in this example has a circular cross-section generally conforming to the shape and size of the consumable part 4 so as to provide a smooth transition between the two parts at the interface 6. In this example, the control unit has a length of around 8 cm so the overall length of the non-combustible aerosol provision system when the consumable part and control unit are coupled together is around 12 cm. However, and as already noted, it will be appreciated that the overall shape and scale of an non-combustible aerosol provision system implementing an embodiment of the disclosure is not of primary significance to the principles described herein.

The air inlet 28 connects to an air path 30 through the control unit 2. The control unit air path 30 in turn connects to the cartridge air path 52 across the interface 6 when the control unit 2 and consumable part 4 are connected together. The pressure sensor chamber 18 containing the pressure sensor 16 is in fluid communication with the air path 30 in the control unit 2 (i.e. the pressure sensor chamber 18 branches off from the air path 30 in the control unit 2). Thus, when a user inhales on the mouthpiece opening 50, there is a drop in pressure in the pressure sensor chamber 18 that may be detected by the pressure sensor 16 and also air is drawn in through the air inlet 28, along the control unit air path 30, across the interface 6, through the aerosol generation region in the vicinity of the vaporizer 65 (where an aerosol generated from the aerosolizable material becomes entrained in the air flow when the vaporizer is active), along the cartridge air path 52, and out through the mouthpiece opening 50 for user inhalation.

The battery 26 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in non-combustible aerosol provision systems and other applications requiring provision of relatively high currents over relatively short periods. The battery 26 may be recharged through a charging connector in the control unit housing 12, for example a USB connector.

The user input button 14 in this example is a conventional mechanical button, for example comprising a spring mounted component which may be pressed by a user to establish an electrical contact. In this regard, the input button may be considered to provide a manual input mechanism for the non-combustible aerosol provision system, but the specific manner in which the button is implemented is not significant. For example, different forms of mechanical button or touch-sensitive button (e.g. based on capacitive or optical sensing techniques) may be used in other implementations. The specific manner in which the button is implemented may, for example, be selected having regard to a desired aesthetic appearance.

The display 24 is provided to give a user a visual indication of various characteristics associated with the non-combustible aerosol provision system, for example current power and/or temperature setting information, remaining battery power, and so forth. The display may be implemented in various ways. In this example the display 24 comprises a conventional pixilated LCD screen that may be driven to display the desired information in accordance with conventional techniques. In other implementations the display may comprise one or more discrete indicators, for example LEDs, that are arranged to display the desired information, for example through particular colors and/or flash sequences. More generally, the manner in which the display is provided and information is displayed to a user using the display is not significant to the principles described herein. Some embodiments may not include a visual display and may include other means for providing a user with information relating to operating characteristics of the non-combustible aerosol provision system, for example using audio signaling or haptic feedback, or may not include any means for providing a user with information relating to operating characteristics of the non-combustible aerosol provision system.

The control circuitry 20 is suitably configured/programmed to control the operation of the non-combustible aerosol provision system to provide functionality in accordance with embodiments of the disclosure as described further herein, as well as for providing conventional operating functions of the non-combustible aerosol provision system in line with the established techniques for controlling such devices. The control circuitry (processor circuitry) 20 may be considered to logically comprise various sub-units/circuitry elements associated with different aspects of the non-combustible aerosol provision system's operation in accordance with the principles described herein and other conventional operating aspects of non-combustible aerosol provision systems, such as display driving circuitry and user input detection. It will be appreciated the functionality of the control circuitry 20 can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and/or one or more suitably configured application-specific integrated circuit(s)/circuitry/chip(s)/chipset(s) configured to provide the desired functionality.

As is common for non-combustible aerosol provision systems, the non-combustible aerosol provision system of FIG. 1 supports three basic operating states, namely an “off” state, an “on” state, and a “standby” state.

In the off state, the non-combustible aerosol provision system is unable to generate aerosol (i.e. the power supply control circuitry is prevented from supplying power to the vaporizer/heater in the off state). The non-combustible aerosol provision system may, for example, be placed in the off state between use sessions, for example when the non-combustible aerosol provision system might be set aside or placed in a user's pocket or bag.

In the on (or active) state, the non-combustible aerosol provision system is actively generating aerosol (i.e. the power supply control circuitry is providing power to the vaporizer/heater). The non-combustible aerosol provision system will thus typically be in the on state when a user is in the process of inhaling aerosol from the non-combustible aerosol provision system.

In the standby state the non-combustible aerosol provision system is ready to generate aerosol (i.e. ready to apply power to the electric heater) in response to user activation, but is not currently doing so. The non-combustible aerosol provision system will typically be in the standby state when a user initially exits the off state to begin a session of use (i.e. when a user initially turns on the non-combustible aerosol provision system), or between uses during an ongoing session of use (i.e. between puffs when the user is using the non-combustible aerosol provision system). It is more common for non-combustible aerosol provision systems using liquid aerosolizable material to revert to the standby mode between puffs, whereas for non-combustible aerosol provision systems using solid aerosolizable material may more often remain on between puffs to seek to maintain the aerosolizable material at a desired temperature during a session of use comprising a series of puffs.

To generate an aerosol using the vapor provision system of FIG. 1 , electrical power from the battery 26 is supplied to the heater 65 under control of the control circuitry 20. When the non-combustible aerosol provision system is on, i.e. actively generating an aerosol, power may be supplied to the heater in a pulsed fashion, for examples using a pulse width modulation (PWM) scheme to control the level of power being delivered. Thus, the power supplied to the electric heater during a period of aerosol generation may comprise an alternating sequence of on periods during which power is connected to the electric heater and off periods during power is not connected to the electric heater. The cycle period for the pulse width modulation (i.e. the duration of a neighboring pair of an off and an on period) is in this example 0.020 s (20 ms) (i.e. the pulse width modulation frequency is 50 hertz). The proportion of each cycle period during which power is being supplied to the heater (i.e. the length of the on period) as a fraction of the cycle period is the so-called duty cycle for the pulse width modulation. In accordance with certain embodiments of the disclosure, the control circuitry of the non-combustible aerosol provision system may be configured to adjust the duty cycle for the pulse width modulation to vary the power supplied to the heater, for example to achieve a target level of average power or to achieve a target temperature.

As noted above, some non-combustible aerosol provision systems may include means for measuring a temperature of a heater for vaporizing aerosolizable material. Some of these non-combustible aerosol provision systems may use a separate temperature sensor for measuring the temperature of the heater while others may measure an electrical resistance for the heater and use this to determine its temperature by taking account of how electrical resistance varies with temperature. One drawback of using a separate temperature sensor to measure temperature is increased structural complexity and part count. One drawback of solely relying on electrical resistance to measure temperature is low sensitivity due to the relatively low temperature coefficient of resistance associated with some materials commonly used for heaters in non-combustible aerosol provision systems.

Whereas the embodiments discussed above with reference to FIG. 1 have to some extent focused on devices having a liquid aerosolizable material, as already noted the same principles may be adopted for devices based on other aerosolizable materials, for example solid materials, such as plant derived materials, such as tobacco derivative materials, or other forms of aerosolizable material, such as gel, paste or foam based aerosolizable materials. Thus, the aerosolizable material may, for example, be in the form of a solid, liquid or gel which may or may not contain nicotine and/or flavorants. In some embodiments, the aerosolizable material may comprise an “amorphous solid”, which may alternatively be referred to as a “monolithic solid” (i.e. non-fibrous). In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosolizable material may for example comprise from about 50 wt %, 60 wt % or 70 wt % of amorphous solid, to about 90 wt %, 95 wt % or 100 wt % of amorphous solid.

The aerosolizable material (which may also be referred to as aerosol generating material or aerosol precursor material) may in some embodiments comprise a vapor- or aerosol-generating agent or a humectant. Example such agents are glycerol, propylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

Furthermore, and as already noted, it will be appreciated the above-described approaches may be implemented in non-combustible aerosol provision systems, e.g. electronic smoking articles, having a different overall construction than that represented in FIG. 1 . For example, the same principles may be adopted in an non-combustible aerosol provision system which does not comprise a two-part modular construction, but which instead comprises a single-part device, for example a disposable (i.e. non-rechargeable and non-refillable) device. Furthermore, in some implementations of a modular device, the arrangement of components may be different. For example, in some implementations the control unit may also comprise the vaporizer with a replaceable cartridge providing a source of aerosolizable material for the vaporizer to use to generate aerosol.

Furthermore still, in some examples the non-combustible aerosol provision systems may further include a flavor insert (flavoring element), for example a receptacle (pod) for a portion of tobacco or other material, arranged in the airflow path through the device, for example downstream of the vaporizer, to impart additional flavor to aerosol generated by the vaporizer (i.e. what a hybrid type device).

As used herein, the terms “flavor” and “flavorant”, and related terms, refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. The materials may be imitation, synthetic or natural ingredients or blends thereof. The material may be in any suitable form, for example, oil, liquid, or powder.

In accordance with certain embodiments of the disclosure an non-combustible aerosol provision device comprises control circuitry, a power source and an aerosol generator configured to generate an aerosol from the aerosolizable material, wherein the control circuitry performs the method of causing delivery of power from the power source to the aerosol generator for a aerosol generation event in response to a user input, determining the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor. Advantageously, by basing the determination of the rate of aerosol generation on a dynamic factor, a more accurate determination of aerosol usage can be achieved.

As noted above, some non-combustible aerosol provision systems may rely on measurements of electrical resistance to determine abnormal conditions once an aerosolizable material has been consumed. However as well as having low sensitivity due to the relatively low temperature coefficient of resistance associated with some materials commonly used for heaters in non-combustible aerosol provision systems, the determination of the temperature of the heater can be significantly affected by any variance in the resistance of the heater (e.g. due to manufacturing tolerances). Example embodiments of the disclosure instead exploit the determination of a rate of aerosol generation which is adjusted based on a dynamic factor to determine consumption of aerosolizable material. In some examples, by comparing to a known or estimated amount of aerosolizable material (e.g. the amount of liquid in a reservoir) the control circuitry 20 can estimate when the aerosolizable material has been depleted or is near depletion. By amount it is meant a measure of the quantity, such as mass or volume. This estimation can be useful as it can provide a user with information concerning the amount of aerosolizable material in the system, and/or assist in triggering one or more other detection mechanisms.

The rate of generation of aerosol depends upon a number of static factors related to the system configuration and hence the environment in which the aerosol is produced. Static factors include factors such as the energy supplied to the aerosolizable material (e.g. power multiplied by time), the composition of the aerosolizable material, and also factors related to the aerosol generator (e.g. size, type) and the airflow configuration (e.g. the dimensions of the volume of airflow channel adjacent to the aerosol generator). The factors are termed “static” because they do not generally vary either during or between different aerosol generation events (i.e. puff events). For example, for two puffs using the same aerosol generator, the aerosol generator and the airflow configuration will not change (e.g. the static factor is a constant). In the example of energy, while power can be increased and therefore the rate of aerosol generation (e.g. aerosol production) is also increased, this is still a static variable as the rate is considered to be static in relation to the amount of energy supplied (e.g. systems can configured to equate 1 Joule to the production of a certain amount of aerosol regardless of whether that Joule is provided over 1 second or 0.5 seconds). Static variables can be taken into account when providing a determination of the amount of aerosol generated from the aerosolizable material; however they provide reduced accuracy when used solely to determine an amount of aerosol that has been generated.

Advantageously, it has been found that the determination of the amount of aerosol generated from the aerosolizable material can be improved by taking into account dynamic factors. The factors are termed “dynamic” because they can vary between different aerosol generation events and/or within an aerosol generation event. For example, the dynamic factor can have a first value during a first aerosol generation event and a second value during a second aerosol generation event (e.g. the dynamic factor is a variable). Dynamic factors include factors such as intra-puff duration, inter-puff duration, cumulative puff duration, airflow rate, amount of aerosolizable material, and ambient temperature.

The rate of aerosol generation can be dependent on the intra-puff duration (e.g. the duration of an aerosol generation event). The rate of aerosol generation increases as intra-puff duration increases. Without being bound by theory, this is considered to be because energy losses to the surrounding components (e.g. wick, support structures, airflow channel walls) decreases as the intra-puff duration increases. In some examples, intra-puff duration is determined by a user during a puff (for example, based on a user starting to puff and ceasing to puff, or on a user pressing a button and ceasing to press a button). In some examples, intra-puff duration is determined by a user prior to a puff (e.g. by selecting an inter-puff duration using a user interface prior to taking the puff). Typically, the intra-puff duration is between 1 and 8 seconds, and preferably between 2 and 4 seconds.

The rate of aerosol generation can be dependent on the inter-puff duration (e.g. time between aerosol generation events). The rate of aerosol generation decreases as inter-puff duration increases. Without being bound by theory, this is considered to be because the temperature of the aerosol generator, the aerosolizable material and the surrounding components (e.g. wick, support structures, airflow channel walls) decreases as the time since the last puff increases. As such, if there is a shorter period of time between two sequential puffs then the aerosol generator, the aerosolizable material and, to some extent, the surrounding components have been effectively pre-heated. For substantially long inter-puff durations (e.g. more than 5 minutes) the effect of the inter-puff duration on rate becomes constant because the aerosol generator, the aerosolizable material and the surrounding components have reached equilibrium with their surroundings (e.g. they have reached ambient temperature). In some examples, when the device has been off for a substantial amount of time or when the aerosol generator and/or aerosolizable material is being used for the first time, then there will not be a suitable previous aerosol generation event, and instead for the purposes of determining a rate it can be considered that any adjustment based on the inter-puff duration is substantially zero.

The rate of aerosol generation can be dependent on the amount of aerosolizable material. Without being bound by theory, it is considered that aerosolizable material is used up in each puff and that as a result, the supply of readily available aerosolizable material reduces over time. For solid aerosolizable materials, waste products may accumulate with increased numbers of puffs and may lead to a reduction in the rate of aerosol generation as they absorb a certain amount of energy rather than the useful aerosolizable material. For some liquid aerosolizable materials the liquid is fed to the aerosol generator through one or more pathways or wicking materials. As liquid is used up, the pressure forcing liquid towards the aerosol generator can reduce (i.e. there is less liquid effectively pushing liquid towards the aerosol generator). The rate of aerosol generation can therefore decrease as the rate of resupply of liquid aerosolizable material is reduced. In some examples, the amount of aerosolizable material can be measured using any of a resistance-based mechanism, a capacitance-based mechanism, an optical-based mechanism, and a mass-based mechanism.

The rate of aerosol generation can be dependent on the cumulative puff duration (total time of all puffs) for a particular aerosol generator (e.g. cumulative over the time between the device identifying changes of the aerosol generator). Without being bound by theory, it is considered that the aerosol generator can deteriorate over time and become less efficient. This can be particularly problematic for devices where the same aerosol generator is used with multiple aerosolizable materials over its lifetime. The rate of aerosol generation can therefore decrease with cumulative puff duration for a particular aerosol generator.

The rate of aerosol generation can be dependent on the airflow rate through the device, and in particular past the aerosol generator. Without being bound by theory, it is considered that increased airflow leads to increased cooling of the aerosol generator, as well as the aerosolizable material and the surrounding components. As such, the rate of aerosol generation decreases as the airflow rate increases.

The rate of aerosol generation can be dependent on the ambient temperature of the device and surrounding environment. Without being bound by theory, it is considered that increased ambient temperatures lead to an increased rate of aerosol generation because the aerosol generator heats up to a target temperature quicker for an equivalent power. Furthermore, the temperature difference between the aerosol generator and the surroundings is less, so less energy is lost to the surroundings.

By taking into account any one of these dynamic variables when determining the rate of aerosol generation, a more accurate determination of the amount of aerosol generated during an aerosol generation event is achieved. Furthermore, by taking into account multiple of these dynamic variables when determining the rate of aerosol generation, the accuracy of the determination of the amount of aerosol generated during an aerosol generation event is further improved.

FIG. 2 is a flow diagram schematically representing some operating aspects of the non-combustible aerosol provision system of FIG. 1 in accordance with certain embodiments of the disclosure.

The processing starts in S21 in which the non-combustible aerosol provision device 1 is in a “standby” state or an “on” state. Insofar as is relevant here, the processing represented in FIG. 2 is the same regardless of whether the non-combustible aerosol provision system starts in the standby mode in S21 because it has just been switched out of the off state to begin a session of use or because it is between puffs during an ongoing session of use. The manner in which the non-combustible aerosol provision system is caused to switch from the off state to the standby state will be a matter of implementation and is not significant here. For example, to transition from the off state to the standby state the user may be required to press the input button 14 in a particular sequence, for example multiple presses within a predetermined time.

In S21 the control circuitry 20 causes delivery of power from the power source to the aerosol generator for an aerosol generation event in response to a user input. In some examples, the control circuitry causes a substantially constant average power to be delivered to the aerosol generator.

In some examples, the power is delivered using pulse width modulation, wherein a duty cycle of the pulse width modulation is used to control the size of the pulse width and, therefore, to provide a target power. In some examples, a constant direct current (DC) is applied to the aerosol generator (the control circuitry 20 may be configured to control a DC to DC converter to provide a target power).

In some examples, the control circuitry 20 is configured to provide power at a first power level for a first duration and to provide power at a second power level for a second duration. In some examples, the control circuitry 20 is configured to provide power during a first “preliminary” phase at the first level of power, and may be configured to provide power during a second “main” phase at the second level of power. In these examples, the control circuitry 20 is configured to transition between the first and second power levels after a set time.

In some examples, the control circuitry 20 is configured to provide power at a first level of power when a “normal” mode of operation is selected and to provide power at a second level of power when a “boost” mode of operation is selected. In these examples, the control circuitry 20 is configured to identify an input from the user which triggers the transition from the “normal” mode to the “boost” mode, or vice versa.

As previously stated, the control unit 2 can comprise a user input mechanism such as a button 14 or an inhalation sensor (puff detector) 16. The control circuit 20 is configured to identify, or otherwise receive, a user input based on the user interacting with the user input mechanism and/or the inhalation sensor. The control circuitry 20 is configured to control an aspect of the device in response to the user input, such as causing the delivery of power from the power source to the aerosol generator in response to the user input.

In some examples, the control circuitry is configured to monitor the output from the inhalation sensor 16 to determine when a user is inhaling (i.e. a user input) through the mouthpiece opening 50 of the non-combustible aerosol provision system so that power can be automatically supplied to the vaporizer 65 to generate aerosol in response to user inhalation.

In some examples a user manually activates a user input mechanism (i.e. a user input) such as a button 14/switch to trigger aerosol generation (e.g. by the control circuitry 20 causing power to be supplied to the vaporizer 65). It will be appreciated that the user input mechanism may not be a button, but can be any mechanism which the user can actuate to cause an input. For example, the user input mechanism may be a slider, a dial, a touch screen etc. In some examples, the control circuitry 20 is able to receive inputs from both an inhalation sensor 16 and a user input mechanism and is able to select between a first mode and a second mode of operation based on the combined inputs.

In some examples, the duration of the aerosol generation event (i.e. the intra-puff duration or aerosol generation event duration) corresponds to the time in which the control circuitry 20 receives the user input. In some examples, the time in which the control circuitry receives the user input is the time in which the user input exceeds a certain threshold (e.g. for a inhalation sensor or a pressure sensitive button, the time in which the pressure applied by the user exceeds the threshold). In some examples, the intra-puff duration (i.e. the aerosol generation event duration) corresponds to the time between the control circuitry 20 receiving a first user input indicating a start point and a second user input indicating an end point. For example, if the user input mechanism has a number of selectable states (e.g. a switch having a first state and a second state), then the user can select a first state to cause the control circuitry to cause power to be supplied to the aerosol generator (i.e. the start point) and can select a second state to cause the control circuitry to stop causing power to be supplied to the aerosol generator (i.e. the end point).

In [[step]] S22, the control circuitry 20 determines the amount of aerosol generated from the aerosolizable material, where the aerosol has been generated in response to the user input at S21. The control circuitry 20 is configured to base the determination on a rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor, such as the duration of the aerosol generation event (i.e. the intra-puff duration). As previously stated, the rate of aerosol production is not only dependent on static factors such as the power supplied (e.g. a constant power does not produce a constant rate of aerosol generation), the composition of the aerosolizable material, or the configuration of the device, but is instead dependent on dynamic factors which can differ for different aerosol generating events and/or within a single aerosol generation event.

For example, the inter-puff duration increases the rate of aerosol generation increases (i.e. increased levels of aerosol are generated later on during a puff). As such, the amount or volume of aerosol produced during an inhalation event (i.e. a puff) is not linearly dependent on the intra-puff duration. Therefore to provide an improved estimate of the amount of aerosol generated during a puff, the change in the rate of aerosol generation due to the intra-puff duration can be taken into account.

Thus, the approach of FIG. 2 represents an improved method of determining an amount of aerosol that has been produced in response to a user input (i.e. during an inhalation or puff event). An improved determination can be used for a plurality of reasons; for example to provide an improved estimate of the amount of aerosol generated over a certain amount of time or number of puffs, to provide an improved estimate of the amount of aerosolizable material remaining in a source of aerosolizable material, to determine when the user must conduct an action (such as changing the source of aerosolizable material and/or a subsidiary component e.g. tobacco pod), and/or to restrict operations (e.g. activating the aerosol generator) which may damage components of the system when the amount of remaining aerosolizable material is considered to be beneath a threshold.

Table 1 provides results for a first liquid aerosolizable material used with an non-combustible aerosol provision system having an aerosol generator comprising a resistive heater which is supplied with liquid from a liquid reservoir by a wick extending between the heater and the liquid reservoir. The non-combustible aerosol provision system tested is therefore substantially similar to the example described in relation to FIG. 1 . The non-combustible aerosol provision system tested further comprises control circuitry configured to cause power to be supplied to the heater in response to an input (i.e. a laboratory controlled input mimicking a user input). The control circuitry is configured to supply of 2.5-2.7 J of energy during a first constant power phase (e.g. a preheat phase), before supplying power at 7.5 W during a second phase using PWM. The first phase typically lasts around 200 ms dependent mainly on the battery voltage. The second phase lasts the remainder of the time.

In each test an equivalent liquid aerosolizable material (i.e. same composition and amount) was tested. The mass of the aerosol generator with liquid reservoir was weighed, before repeatedly activating the heater for a set duration (e.g. 3 s, 4 s, or 6 s) with pauses of at least 20 seconds between activations. After a series of heater activations (e.g. 20 activations) are completed, the aerosol generator and liquid reservoir was weighed to determine the gravimetric quantity of liquid used. The heater was repeatedly activated with additional series of heater activation until it was deemed that the liquid aerosolizable material was depleted. The test was repeated for different set durations.

TABLE 1 Puff duration 3 secs 4 secs 6 secs Puffs per cartridge 228 156 89 Total mass loss, mg ~1800 ~1800 ~1800 Total heater activation time, s 637 591 512 [600:678] [560:642] [490:532]

The results show that for longer puff lengths the total time the heater needs to be activated to aerosolize the same amount of liquid is reduced. For example, for a sequence of 3 second puffs the total heater activation time was 637 seconds, for a sequence of 4 second puffs the total heater activation time was 591 seconds, and for a sequence of 6 second puffs the total heater activation time was 512 seconds. Therefore there is a difference of 125 seconds between aerosolizing for 6 seconds repetitions and aerosolizing for 3 seconds repetitions. Errors for total heater activation time values are provided in square brackets.

The rate of mass loss (e.g. the rate of aerosol generation) can be calculated for each specific sequence as the total mass of the liquid before testing (˜1800 mg) divided by the total heater activation time. Therefore for a sequence of 6 second heater activations the rate of mass loss was measured as 3.52 mg/s, for a sequence of 4 second activations the rate of mass loss was measured as 3.05 mg/s, and for a sequence of 3 second activations the rate of mass loss was measured as 2.83 mg/s.

Without being bound by theory, and as briefly above, it is believed that the rate of aerosol generation increases with time as the temperature of surrounding components has increased and therefore less energy is lost to them. In other words, towards the beginning of a puff, the surrounding components can be significantly colder than the aerosol generator (e.g. a heater may heat quickly to around 200° C. while the surrounding components may be at room temperature). A temperature gradient forms between the aerosol generator and the surrounding components with energy flowing from the high temperature heater to the low temperature surroundings. Broadly speaking, the rate of energy/heat flow is proportional to the difference in temperatures and the heat transfer coefficients for the various mechanisms of heat transfer (e.g. conduction, convection). As such the rate of energy flow to the surroundings, which may be considered a loss, reduces as the difference in temperatures reduces during a puff.

For non-combustible aerosol provision systems comprising an aerosolizable material that is continually resupplied during aerosolization (e.g. a liquid aerosolizable material that is wicked, or otherwise transported, to the vicinity of the heater), it is further considered that the heat lost to the surrounding components may, to some extent, pre-heat the aerosolizable material further from the aerosol generator. Advantageously, as a result less energy is required to bring the pre-heated aerosolizable material to the vaporization temperature (i.e. because it is at a higher temperature to start with) than compared to an aerosolizable material at room temperature. Additionally for a pre-heated liquid aerosolizable material, the viscosity may be reduced compared to a liquid at room-temperature and therefore resupply of the liquid to aerosol generator is improved.

FIG. 3 is a graph representing the rate of mass loss for different length heater activations in accordance with the results provided in Table 1. The x-axis is puff duration in seconds and the y-axis mass loss per second in mg/s. The term “puff duration” is used interchangeably with the term “aerosol generation event duration” as discussed above, and refers to the period of time in which a power is supplied to the aerosol generator when a user input indicates a user is puffing or inhaling through the system. In some examples where a user input is provided by a mechanism such as a button, the aerosol generation event can also include an initial heating period where the heater is activated but the user has not yet started puffing (for example, the use may depress a button as they bring the device towards their mouth but may not draw aerosol until a seal has been formed by their lips over the mouthpiece outlet).

A dashed line labelled “expected” in FIG. 3 details the expected mass loss per second if the mass loss was proportional to the power applied. In other words the “expected” line is dependent (at least in part) on a static factor relating to the power supplied (e.g. 7.5 W) which is constant irrespective of puff duration. Hence for examples which only used a static factor the expected rate of mass loss is constant for all puff durations.

A solid line labelled “measured” details a linear fit of the measured mass loss per second. The “measured” line differs significantly from the “expected” line, particularly at long puff durations. The fit of the “measured” line has the formula Y=α*X+c where a and c are constants, with a determining the gradient of the line and c the Y-intercept. For the particular tests shown, α approximately equals 0.23 and c approximately equals 2.13. The value of c may largely be determined by static factors such as the composition of the aerosolizable material and the aerosol generator type, whereas the value of a represents the effect of dynamic factors on the mass loss per second, such as the temperature of the surroundings of the heater increasing during a puff.

In some examples, the control circuitry 20 is configured to determine the duration of the aerosol generation event (i.e. the intra-puff duration) in which power is supplied to an aerosol generator and can compare the duration to the formula to obtain a rate of mass loss for that particular puff. The total mass loss (e.g. the amount of aerosol generated) during that puff can be calculated by multiplying the rate of mass loss by the duration. For example, for a puff of 3.5 seconds, the average rate of mass loss is 2.94 mg/s and the total mass loss during the puff is 10.29 mg.

In other examples, rather than calculating a rate of mass loss, the control circuitry 20 calculates a total mass loss dependent on puff length. This removes the need to first calculate the rate and secondly multiply the rate by the time. However, in contrast to the approximately linear fit shown in FIG. 3 , the dependency of total mass loss per puff length is approximately a second order polynomial. Therefore while a second order polynomial fit can also be used to provide an improved estimation of the mass loss, the mathematical operations behind the estimation are more complicated for the control circuitry.

The cumulative total mass loss for a sequence of puffs (of any puff length) can be calculated using the formula

Cumulative mass loss=Σ_(puff=1) ^(puff=n)[α×puff duration(x)+c]×puff duration(x),

where puff duration (x) is the duration of a respective puffs in the series 1 to n puffs, and α and c are predetermined constants (calculated by fitting a line to test data as defined above).

Similarly a remaining mass of aerosolizable material can be calculated using the formula

Mass_(remaining)=Mass_(initial)−Σ_(puff=1) ^(puff=n)[α×puff duration(x)+c]×puff duration(x),

where Mass_(initial) is the initial mass of aerosolizable material. Alternatively, the calculation can be simplified and written as Mass_(remaining)=Mass_(initial)−Cumulative mass loss.

It will be appreciated that while the above calculations are in terms of mass, if the density of a material is known then the above rates and mass amounts can be converted into volumes.

As is shown in the above calculations, the rate of aerosol generation is dependent on the dynamic factor of intra-puff duration (i.e. “puff duration (x)” in the above equations). As the intra-puff duration increases the rate of aerosol generation (i.e. the term in [ . . . ]) increases. The rate of aerosol generation as calculated is an average for the whole of the puff and is multiplied by the puff duration to obtain the amount of aerosol generated (e.g. the mass lost during the aerosol generation event).

Table 2 provides results for a second liquid aerosolizable material used with an non-combustible aerosol provision system having an aerosol generator comprising a resistive heater which is supplied with liquid from a liquid reservoir by a wick extending between the heater and the liquid reservoir. The non-combustible aerosol provision system tested is therefore substantially similar to the example described in relation to FIG. 1 and the system used to provide table 1. The non-combustible aerosol provision system tested further comprises control circuitry configured to cause power to be supplied to the heater in response to an input (i.e. a laboratory controlled input mimicking a user input). The control circuitry is configured to supply 2.5-2.7 J of energy during a first constant power phase (e.g. a preheat phase), before supplying power at 7.5 W during a second phase using PWM. The first phase typically lasts around 200 ms dependent mainly on the battery voltage. The second phase lasts the remainder of the time.

In each test an equivalent liquid aerosolizable material (i.e. same composition and amount) was tested. The mass of the aerosol generator with liquid reservoir was weighed, before repeatedly activating the heater for a set duration (e.g. 3 s, 4 s, or 6 s) with pauses of at least 20 seconds between activations. After a series of heater activations (e.g. 20 activations) are completed, the aerosol generator and liquid reservoir was weighed to determine the gravimetric quantity of liquid used. The heater was repeatedly activated with additional series of heater activations until it was deemed that the liquid aerosolizable material was depleted. The test was repeated for different set durations.

TABLE 2 Puff duration 3 secs 4 secs 6 secs Puffs per cartridge 265 179 101 Total mass loss, mg ~1950 ~1950 ~1950 Total heater activation time, s 795 716 606

The results also show, similarly to Table 1, that for longer puff lengths, the total time the heater needs to be activated to aerosolize the same amount of liquid is reduced. For example, for a sequence of 3 second puffs the total heater activation time was 795 seconds, for a sequence of 4 second puffs the total heater activation time was 716 seconds, and for a sequence of 6 second puffs the total heater activation time was 606 seconds. Therefore there is a difference of 189 seconds between aerosolizing for 6 seconds repetitions and aerosolizing for 3 seconds repetitions.

The rate of mass loss (e.g. the rate of aerosol generation) can be calculated for each specific sequence as the total mass of the liquid before testing (˜1950 mg) divided by the total heater activation time. Therefore for a sequence of 6 second heater activations the rate of mass loss was measured as 3.22 mg/s, for a sequence of 4 second activations the rate of mass loss was measured as 2.72 mg/s, and for a sequence of 3 second activations the rate of mass loss was measured as 2.45 mg/s. Additionally, a linear fit of the measured mass loss per second, using the formula Y=α*X+c, leads to a determination of a as approximately equal to 0.25 and c as approximately equal to 1.70.

As previously stated, the value of c may largely be determined by static factors such as the composition of the aerosolizable material and the aerosol generator type. As the first aerosolizable material (Table 1) is different to the second aerosolizable material (Table 2), the value of c has changed.

The rate of aerosol generation is also dependent on the dynamic factor of intra-puff duration (i.e. “puff duration (x)” in the above equations) in line with the example of Table 1, albeit with different constant α and c being used to calculate the rate.

While Tables 1 and 2, FIG. 3 and the associated text are concerned with the effect of the intra-puff duration, it will be appreciated that the control circuitry can be configured to determine the rate of aerosol generation using these and other dynamic factors based on similar calculations. For example, the dependence of the rate of aerosol generation on any of intra-puff duration; inter-puff duration; cumulative puff duration, airflow rate, amount of aerosolizable material, and ambient temperature can first be established (e.g. empirically using laboratory tests). The dependence can then be fitted using a function such as a polynomial function (e.g. a linear or quadratic function), an exponential function, or a logarithmic function. It will be appreciated that other functions known in the art can be used instead. The parameters relating to the fit can then be used by the control circuitry to determine the rate of the aerosol generation for the particular dynamic factor.

A similar method can be used when determining multiple dynamic factors. The combined dependence (i.e. multi-variate dependence) the rate of aerosol generation on any two or more of intra-puff duration; inter-puff duration; cumulative puff duration, airflow rate, amount of aerosolizable material, and ambient temperature can first be established (e.g. empirically using laboratory tests). The combined dependence can then be fitted using a function. The parameters relating to the fit can then be used by the control circuitry 20 to determine the rate of the aerosol generation for the two or more dynamic factors.

In some examples, the control circuitry 20 causes power to be delivered from the power source to the aerosol generator at a first substantially constant average level during a first phase and at a second substantially constant average level during a subsequent main phase. The inter-puff duration can be considered a third “relax” phase.

Different dynamic factors may affect the aerosol generation rate differently in these phases. For example, the rate of aerosol generation may be particularly effected in the second phase by the amount of aerosolizable material in the system, since the second phase can be relatively long compared to the first phase and is therefore more sensitive to changes in remaining aerosolizable material. In some examples, the control circuitry 20 calculates an average rate of aerosol generation across the first and second phases (e.g. the approach taken in relation to Table 1 and 2 above), while in other examples the control circuitry calculates a first rate of aerosol generation in the first phase and a second rate of aerosol generation in the second phase. The first and second rates of aerosol generation can be average rates for the duration of those phases.

In some examples, the control circuitry 20, and/or a separate device, can be configured to calculate a usage amount. The usage amount may be a cumulative amount of aerosol generated from the aerosolizable material and/or a remaining amounting of aerosol that can be generated from the aerosolizable material. Examples of calculation of a cumulative amount and of a remaining amount are provided in the text associated with Table 1 in relation to intra-puff duration. In some examples, the control circuitry, and/or the separate device, is configured to define an upper and/or lower estimate for the usage amount.

In some examples, the control circuitry is configured to compare the usage amount to a threshold, and to control an aspect of the non-combustible aerosol provision system based on the comparison of the usage amount to the threshold.

For example, the aspect of the non-combustible aerosol provision system to be controlled may be the delivery of power to the aerosol generator. In these examples the control circuitry 20 is configured to modulate (e.g. alter or change) the delivery of power from the power source to the aerosol generator in response to a subsequent user input. In some examples, modulating the delivery of power comprises ceasing to supply power to the aerosol generator in response to a subsequent user input. The control circuitry 20 may continue to modulate power until new aerosolizable material is provided and/or the device is reset (e.g. by attaching a new cartridge containing aerosolizable material or by the user performing a reset).

In some examples, controlling an aspect of the non-combustible aerosol provision system comprises controlling a detection mechanism configured to detect whether the aerosol generator is operating under abnormal conditions. For example, the detection mechanism may determine/confirm if there is aerosolizable material in proximity to the aerosol generator. By only controlling the detection mechanism once the above threshold has been exceeded, firstly power can be saved and secondly the occurrence of false positives is reduced. In these examples, the threshold acts as a first trigger for detection of abnormal conditions and the detection mechanism acts as a second trigger that abnormal conditions have been detected. In some embodiments, only when both trigger does the control circuitry 20 deem there to be abnormal conditions. The control circuitry 20 may modulate the delivery of power from the power source to the aerosol generator in response to the second trigger. In particular the control circuitry 20 may cease the supply of power or prevent the further supply of power to the aerosol generator until new aerosolizable material is provided and/or the device is reset.

In some examples, the detection mechanism is any of a resistance-based detection mechanism, a capacitance-based detection mechanism, and an optical-based detection mechanism.

In some examples, the control circuitry 20, and/or a separate device, is configured to calculate the usage amount as a prediction of a remaining total duration of aerosol generation events or a remaining number of aerosol generation events for the aerosolizable material, wherein the prediction is based on the usage amount and a historical data set relating to measured durations of previous aerosol generation events. As such, in these examples the usage amount is a remaining amount. Such a value may be easier to interpret by a user of the device (i.e. more user-friendly).

In some examples, the prediction based on the historical data set relating to measured durations of previous aerosol generation events comprises the prediction being based on: the duration of a most recent previous aerosol generation event, an average duration of a plurality of previous aerosol generation events, or a predicted usage for a plurality of subsequent puff aerosol generation events. By a predicted usage for a plurality of subsequent puff aerosol generation events it is meant that the control circuitry, and/or separate device, makes a prediction of future usage based on the user's behavior previously. The prediction may take into account factors such as day, time and location.

In some examples the control circuitry is configured to write to the memory a record of the aerosol generation event. This record can be used in determining the predicted remaining total duration of aerosol generation events or a remaining number of aerosol generation events for the aerosolizable material. In some examples, the memory is provided in the control circuitry 20. In other examples, the memory is provided in the consumable part 4.

In examples where there is a memory in the consumable part 3, the memory can keep a record of the usage amount for the consumable part. As such if the consumable part 4 is used with a different reusable part 2, the control circuitry of the different reusable part can read the memory to determine a current state of the usage amount (i.e. a current level of aerosolizable material). Additionally, the memory of the consumable part 4 may indicate a starting amount of aerosolizable material.

In some examples, the control circuitry 20 is configured to provide an indication to a user in relation to the usage amount. By in relation, it is meant that an indication is provided to the user in response to a specific usage amount being reached or having been exceeded (e.g. after an absolute usage amount has been reached such as 1000 mg or a relative usage amount has been reached such as 50% of the total amount). In some examples, the indication is provided via visual, audio and/or haptic means. For example the control circuitry 20 can be configured to provide haptic or audio feedback after set amounts of aerosolizable material have been used (e.g. every 200 mg or every 10% of the total amount).

In some examples, the control circuitry provides the indication via a display mechanism. In other examples, the control circuitry provides the indication via a separate device which the control circuitry is in communication with (e.g. wired or wireless communication). In some examples, the control circuitry 20 is configured to communicate the indication of the usage amount to the user during the user input. In examples, the user may be able to interact with the device to obtain an indication of the current estimate of the usage amount (e.g. via a display). Where the indication is via a display mechanism, the indication may comprise the usage amount.

Thus there has also been described a method of operating an non-combustible aerosol provision system comprising control circuitry, a power source and an aerosol generator configured to generate an aerosol from an aerosolizable material, wherein the control circuitry performs the method of causing delivery of power from the power source to the aerosol generator for an aerosol generation event in response to a user input, and determining the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the determined rate of aerosol generation is adjusted based on a dynamic factor.

Thus there has also been described a control unit for use with an electronic non-combustible aerosol provision device comprising: a power source; and control circuitry configured to cause the delivery of power from the power source to an aerosol generator for an aerosol generation event in response to a user input, wherein the aerosol generator is configured to generate an aerosol from an aerosolizable material during the aerosol generation event; wherein the control circuitry is further configured to determine the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor.

Thus there has been described a non-combustible aerosol provision system comprising: a control unit comprising: a power source; and control circuitry configured to cause the delivery of power from the power source to an aerosol generator for an aerosol generation event in response to a user input, wherein the aerosol generator is configured to generate an aerosol from an aerosolizable material during the aerosol generation event; wherein the control circuitry is further configured to determine the amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor; the aerosol generator; and the aerosolizable material.

Thus there has also been described a non-combustible aerosol provision means comprising: power source means; control means configured to cause the delivery of power from the power source means to an aerosol generator means for a period of time in response to a user input, wherein the aerosol generator means is configured to generate an aerosol from an aerosolizable material means; and wherein the control means is further configured to determine the amount of aerosol generated from the aerosolizable material means, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor.

In order to address various issues and advance the art, this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and to teach the claimed invention(s). It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope of the claims. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein, and it will thus be appreciated that features of the dependent claims may be combined with features of the independent claims in combinations other than those explicitly set out in the claims. The disclosure may include other inventions not presently claimed, but which may be claimed in future. 

1. A method of operating a non-combustible aerosol provision system comprising control circuitry, a power source and an aerosol generator configured to generate an aerosol from an aerosolizable material, the method comprising: by the control circuitry: causing delivery of power from the power source to the aerosol generator for an aerosol generation event in response to a user input; and determining an amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the determined rate of aerosol generation is adjusted based on a dynamic factor.
 2. The method of claim 1, wherein the dynamic factor comprises one or more of: an airflow rate; an intra-puff duration; an inter-puff duration; a cumulative puff duration; an amount of aerosolizable material; and an ambient temperature.
 3. The method of claim 1, wherein the determined rate of aerosol generation is one of: an average rate of aerosol generation during the aerosol generation event, or a real-time rate of aerosol generation during the aerosol generation event.
 4. (canceled)
 5. The method of claim 1, wherein the control circuitry causes power to be delivered from the power source to the aerosol generator at a first substantially constant average level during a first phase and at a second substantially constant average level during a subsequent phase of the aerosol generation event.
 6. The method of claim 1, wherein the determined rate of aerosol generation is dependent on a static factor.
 7. The method of claim 6, wherein the static factor comprises at least one factor related to one or more of: energy delivered to the aerosol generator during the aerosol generation event; composition of the aerosolizable material; the aerosol generator; and an airway configuration.
 8. The method of claim 1, wherein the user input comprises at least one of an inhalation or an activation of a user input mechanism.
 9. The method of claim 2, wherein the intra-puff duration is equivalent to a duration of the user input.
 10. The method of claim 1, wherein the method further comprises calculating a usage amount, wherein the usage amount is one of a cumulative amount of aerosol generated from the aerosolizable material or a remaining amounting of aerosol that can be generated from the aerosolizable material.
 11. The method of claim 10, wherein the method further comprises: comparing the usage amount to a threshold; and controlling an aspect of the non-combustible aerosol provision system based on the comparison of the usage amount to the threshold.
 12. The method of claim 11, wherein controlling the aspect of the non-combustible aerosol provision system based on the comparison of the usage amount to the threshold comprises at least one of: modulating the delivery of power from the power source to the aerosol generator, or controlling a detection mechanism configured to detect whether the aerosol generator is operating under abnormal conditions.
 13. (canceled)
 14. The method of claim 12, wherein the detection mechanism is any of a resistance-based detection mechanism, a capacitance-based detection mechanism, and an optical-based detection mechanism.
 15. The method of claim 10, wherein the control circuitry is configured to define at least one of an upper estimate or a lower estimate for the usage amount.
 16. The method of claim 6, wherein the usage amount comprises a remaining amount consisting of a prediction of a remaining total duration of aerosol generation events or a remaining number of aerosol generation events for the aerosolizable material, wherein the prediction is based on the usage amount and a historical data set relating to measured durations of previous aerosol generation events.
 17. The method of claim 16, wherein the prediction based on the historical data set relating to measured durations of previous aerosol generation events comprises the prediction being based on: a duration of a most recent previous aerosol generation event, an average duration of a plurality of previous aerosol generation events, or a predicted usage for a plurality of subsequent puff aerosol generation events.
 18. The method of claim 10, wherein the usage amount comprises a mass or a volume.
 19. The method of claim 10, wherein the method further comprises providing an indication to a user in relation to the usage amount.
 20. The method of claim 19, wherein the indication of the usage amount is at least one of: communicated to the user during the user input, or communicated via at least one of visual means, audio means, or haptic means.
 21. (canceled)
 22. The method of claim 1 wherein the non-combustible aerosol provision system further comprises a memory, and wherein the control circuitry is configured to write to the memory a record of the aerosol generation event.
 23. A control unit for a non-combustible aerosol provision system comprising: a power source; and control circuitry configured to cause delivery of power from the power source to an aerosol generator for an aerosol generation event in response to a user input, wherein the aerosol generator is configured to generate an aerosol from an aerosolizable material during the aerosol generation event, and wherein the control circuitry is further configured to determine an amount of aerosol generated from the aerosolizable material, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor.
 24. A non-combustible aerosol provision system for generating an aerosol from an aerosolizable material, the non-combustible aerosol provision system comprising: the control unit of claim 23; the aerosol generator; and the aerosolizable material.
 25. The non-combustible aerosol provision system of claim 24, wherein the aerosol generator and the aerosolizable material are provided in a consumable configured to detachably couple with the control unit.
 26. The non-combustible aerosol provision system of claim 25, wherein the consumable comprises a memory and wherein the control circuitry is configured to write to the memory a record of the duration of the aerosol generation event.
 27. Non-combustible aerosol provision means comprising: power source means; control means configured to cause delivery of power from the power source means to an aerosol generator means for a period of time in response to a user input, wherein the aerosol generator means is configured to generate an aerosol from an aerosolizable material means, and wherein the control means is further configured to determine the amount of aerosol generated from the aerosolizable material means, in response to the user input, based on a determined rate of aerosol generation, wherein the rate of aerosol generation is adjusted based on a dynamic factor. 